摘要：When the horizontal grid size of a numerical weather prediction (NWP) model is between a few hundred meters and ~ 10 km, referred to as the gray zone, updrafts in convective clouds cannot be fully resolved explicitly and the use of a subgrid convective cloud parameterization scheme is still necessary. Since some critical assumptions in the mass-flux formulation of conventional subgrid convective cloud parameterization become invalid for gray-zone resolutions, it is required for a generalized parameterization to be developed to properly describe subgrid convective clouds. To meet this requirement, a new subgrid convective cloud parameterization scheme that is based on the mass-flux formulation and suitable for gray-zone resolutions has been proposed and preliminarily tested in the Weather Research and Forecasting (WRF) model. This new scheme is automatically adaptive to variation in grid size (i.e., scale-aware), and accounts for microphysical processes consistently with grid-resolved clouds. Numerical experiment of an idealized tropical cyclone shows that this new scheme has a substantial impact on the tropical cyclone’s intensity and precipitation distribution due to the effect of subgrid clouds on the total diabatic heating.
